Color Calculators
Relative luminance, contrast ratio, color temperature, wavelength to RGB, color difference and more color-science tools.
Relative Luminance Calculator
Compute WCAG relative luminance L = 0.2126R + 0.7152G + 0.0722B (linearized).
Contrast Ratio Calculator
Compute WCAG contrast ratio CR = (L_light+0.05)/(L_dark+0.05) from two colors.
Color Temperature Calculator
Approximate RGB from a black-body color temperature T (K) (Tanner Helland).
Wavelength to RGB Calculator
Approximate RGB from a visible wavelength λ (nm, 380–750).
ΔE Color Difference Calculator
Compute CIE76 color difference ΔE from two RGB colors via sRGB→XYZ→Lab.
Color Mix Calculator
Compute the averaged (additive) mix of two RGB colors.
RGB to HSL Calculator
Convert RGB to HSL (hue, saturation, lightness).
HSL to RGB Calculator
Convert HSL (hue, saturation, lightness) back to RGB.
RGB to CMYK Calculator
Convert RGB to CMYK (cyan, magenta, yellow, black) in percent.
RGB to HSV Calculator
Convert RGB to HSV (hue, saturation, value).
Complementary Color Calculator
Compute the complementary color (hue + 180°) from RGB.
Perceived Brightness Calculator
Compute HSP perceived brightness B = √(0.299R²+0.587G²+0.114B²).